Archbishopric of Milan

The Archbishopric of Milan (c. 50 AD-1045) was an Italian city-state located in the present-day Lombardy and Genoa region of northern Italy. Founded by Barnabas, the archbishopric remained in power until 1045, when the Milanese, although still fervent Catholics, overthrew the Holy Roman Empire's influence. In 1045 it became the Duchy of Milan.

History
Barnabas, a Greek Jewish Christian who converted the people of Cyprus to Christianity, traveled to the city of Mediolanium in the 1st century CE to convert the Romans there to Jesus Christ's teachings. Mediolanium became a center of Christianity in the Roman Empire, and Christians bloomed in the city after the ending of the persecution of Christians under Constantine the Great in 330 AD. Mediolanium, later becoming Milano, fell under the control of the Lombardi and later the Franks, but the bishops and archbishops remained in the city. The Holy Roman Empire conquered the city in 772 AD and appointed their own bishops, and Milan became their puppets.

Milan's Holy Roman influence was thrown off in 1045 as Milan realigned with the Papal States during the animosities between the Pope and Emperor, and the Duchy of Milan under Duke Giorgio de Rossi took power.